The so-called terminal hydroxyl group-modified polybutadiene hydrides in which a hydroxyl group is bound to the terminal of the main chain of a polybutadiene hydride have been known. The terminal hydroxyl group-modified polybutadiene hydride can be obtained by subjecting the carbon-carbon double bond of the main chain or side chain in a terminal hydroxyl group-modified polybutadiene to a hydrogenation reaction. For example, in Patent Document 1, hydrogenation of a polyhydroxy polybutadiene at 100° C. in the presence of a carbon supported ruthenium catalyst or alumina supported ruthenium catalyst by holding the system pressure at 50 mg/cm2 (about 4.9 Pa) has been described. In addition, in Patent Document 2, a method of hydrogenating an unsaturated polyhydroxyhydrocarbon polymer characterized by carrying out a hydrogenation reaction by keeping the reaction temperature constant (for example, 120° C.±5° C.) and setting the reaction pressure to a pressure of 35 kg/cm2 (about 3.4 MPa) or less until a hydrogenation rate of 60% or higher is achieved, and then carrying out a hydrogenation reaction by keeping the reaction temperature constant (for example, 120° C.±5° C.) and setting the reaction pressure to a pressure exceeding 35 kg/cm2 until a hydrogenation rate of 99% or higher is achieved, has been proposed.